Project Batagur baska 2018 – EUAC final report
Project Batagur baska – Satellite Monitoring Anton Weissenbacher & Doris Preininger (Vienna Zoo)
The current project is part of the long-term conservation and in situ breeding Project Batagur baska in Bangladesh. Previously, in February 2017 two males were released with transmitters in the vicinity of the Karamjal station in the Sundarbans. In the 2017 trial release, the signal of one animal was lost 3 days later, the individual was presumed captured or dead. The second male was caught by fishermen within two weeks and with the help of the Forest Department was brought back to the station. To take the next necessary steps for the conservation of the critically endangered Northern River terrapin and search for secure habitats for a reintroduction a different release site was selected in the west Sundarbans. This area is less populated and more difficult to reach for fishermen and the western river system and the coastal area of the delta and adjacent islands comprise prospective beach habitats for nesting. The project coordinator Rupali Ghosh together with staff from the Vienna Zoo, the Prokriti O Jibon Foundation (POJF) and the Forest Department released 5 males equipped with satellite transmitter’s right before the breeding season on 2nd October 2018 in the Sundarbans.
End of September 2018 we applied Telonics satellite transmitters (SeaTrkr-4370-4) on five male individuals (Fig. 1) and traveled by boat to the release site (Fig. 2) in the west Sundarbans. Transmitters were attached on the carapace of individuals with Epoxy glue and as security measure Forest Department and POJF contact numbers were attached clearly visible in case terrapins are captured. The new transmitters weigh 190 g and have an operational life period of 1.2 years. The transmitters’ weight is less than 2% of the body weight of the terrapins that were relased.
Figure 1. One of five males with satellite tag before release. Phone numbers of POJF and Forest Department officials are attached on the transmitter.
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Project Batagur baska 2018 – EUAC final report
The release location in the Sundarbans and adjacent islands in the mangrove, coastal ecosystem consists of a complex river system with brackish water and freshwater and is only accessible by boat.
Karamjal station
Release site
Figure 2. Satellite signals transmitted during boat travel from the Karamjal station to the release site. Release on 2nd October 2018.
At the pint of writing, two of five males have been found dead in the Sundarbans in October and November 2018. One of these males got caught in a permanent net close to the ocean and the other got stuck in the mangrove forest and we noticed that the signals were consistently sent from the same location and observed no movement pattern. The individual were discovered by the Forest Department. Both transmitters have been recovered by the Forest Department and were shut off. One male traveled to India and the Forest Department in India is constantly informed about the activity of the terrapin. Two males are using the river system of the Bangladesh Sundarbans to forage and currently send constant signals (See also supplementary material for tracking information).
Conclusion Conservation breeding and head-starting in both the Bhawal National Park and the Karamjal station are the foremost importance to secure the survival of the critically endangered species. Nevertheless we aim to eventually reintroduce the species in the river system of the Sundarbans. It is still unknown if the terrapin breeds and nests in the brackish river system or in coastal areas. First quantitative and qualitative observation of migration routes of the released males show differing movement up- and downstream from the release site of the terrapins and are yet highly uncertain to determine habitats for reintroduction. According to the current observation a sustainable reintroduction of terrapins remains unsecure and is only appropriate if, terrapins can be protected to a certain amount and monitoring shows that the terrapins can survive in the Sundarbans. First results demonstrate the precarious situation of the natural habitat of the terrapins however only a sufficient sample size of released animals will allow us to make constructive future implementation for the species.
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Project Batagur baska 2018 – EUAC final report
Project costs for satellite monitoring of five males: Equipment Transmitter Telonics (á 1740 x 5) EUR Data converter, freight, service fees until 12/2018 10688
Field visit for transmitter release - 1 trip to West Sundarbans BDT EUR Car, toll, ferry 81112 855 Fuel for Boat 16800 177 Food 21529 227 Boat 152000 1602 Flight (Rupali Ghosh) (INR) 44002 544 Flight (Rupali Ghosh) 5300 56 Accommodation 44400 468 Turtle catch, misc. (tips, tools etc.) 28307 298 4227 Total for satellite transmitter release of 5 males Sep./Oct. 2018 14915 Equipment funded by EUAC to the Vienna Zoo -5000 Equipment funded by DGHT & ZGAP to the Vienna Zoo -5000 TCF funded to the project partner Turtle survival alliance -3300 Remaining costs covered by the Vienna Zoo 1615
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Supplementary material - Vienna Zoo -Dec. 2018 Project Batagur Baska
Male 600
Released : 2.Oct.2018
Last location signal: 12.Nov. 2018
Last location: Hemnagar, India
Travel route: - South to Bay of Bengal (10.Oct) - North upstream - Across Indian border (2. Nov) Supplementary material - Vienna Zoo -Dec. 2018 Project Batagur Baska Location: North Sundarbans Male 597 Travel route: Released : 2.Oct.2018 - Continuous travel upstream (3. Dez) - Movement south approx. 8km (10.Dez) Last location signal: 15. Dec. 2018
Supplementary material - Vienna Zoo -Dec. 2018 Project Batagur Baska Location: Mid-West Sundarbans Male 598 Travel route: Released : 2.Oct.2018 - Upstream to urban area (16. Oct) - Up and down mov. in the northern area (5.Nov) Last location signal: - No signal until 22. Nov – still in northern area 16. Dec. 2018 - 34 km downstream (26. Nov) - North movement (8.Dec) - South movement to last location Supplementary material - Vienna Zoo -Dec. 2018 Location: Project Batagur Baska South-west coastline
Male 571 Travel route:
- Upstream movement north of release site (23.Oct) Released : 2.Oct.2018 - Movement south to coast of Bay of Bengal (28.Oct)
- Movement along coast westward ((8. Nov) Last location signal: - Along coast to urban area (14. Nov) 17.Nov.2018 - Found along coast, caught in net (17. Nov)
Transmitter recovered on 17. Nov
Supplementary material - Vienna Zoo -Dec. 2018 Location: Project Batagur Baska Close to release site Male 571 Travel route: - Movement south from release site Released : 2.Oct.2018 - Stuck in mangrove forest, constant signals from same location - Found by Forest Department staff Last location signal: - Transmitter recovered on 23. Oct 23.Oct.2018